The industry’s smallest class (1608 size) of two-color chip LEDs, dubbed SML-D22MUW, features a special design that improves reliability along with a backside electrode configuration that supports high-resolution displays.
Conventional numerical displays use a single color to indicate numbers, but there is a growing need to change the color to make it easier to recognize abnormalities. However, this typically entails utilizing two separate LEDs, which doubles the mounting area along with development costs, or opting for a standard two-color LED that also increases board size.
In contrast, proprietary technologies and processes allowed ROHM to integrate two chips in the same package size as conventional single-color LEDs, making it possible to emit multiple colors in a smaller footprint. Board space is reduced by 35% over standard 1.5 x 1.3-mm two-color LEDs, contributing to thinner displays. And after taking into consideration usage conditions during reflow, countermeasures were adopted that prevents solder penetration within the resin package to ensure greater reliability.
1. Class-leading compact size contributes to smaller, thinner devices — In addition to element miniaturization, the SML-D22MUW leverages PICOLED mounting and wire bonding technologies to mount two chips (red and green) in a compact 1.6 x 0.8-mm package – the same size as conventional single-color LEDs. Also, the extremely close configuration of color elements results in excellent color mixing properties that make it possible to produce not only red and green colors, but a number of intermediate colors as well.
2. Solder penetration countermeasure ensures superior reliability — Incorporating a stopper called a ‘resist’ before the gold plating process blocks the gold pattern (that features good wettability). This prevents solder penetration into the resin, eliminating failures due to short-circuits and contributing to greater reliability.
3．Backside electrode configuration supports high-resolution display — Adopting a backside electrode design allows mounting in narrow spaces, enabling high-definition display in dot matrix and other applications.
The LEDs are available now and priced at $0.136/unit (3,000 pcs)
ROHM Semiconductor, 2323 Owen Street, Santa Clara, CA 95054, USA